CVE-2018-1000071 in RoundCube
Summary
by MITRE
roundcube version 1.3.4 and earlier contains an Insecure Permissions vulnerability in enigma plugin that can result in exfiltration of gpg private key. This attack appear to be exploitable via network connectivity.
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Analysis
by VulDB Data Team • 02/21/2023
The vulnerability identified as CVE-2018-1000071 affects Roundcube webmail applications version 1.3.4 and earlier, specifically within the enigma plugin component. This issue represents a critical security flaw that stems from improper permission handling in the cryptographic plugin responsible for GPG encryption operations. The vulnerability allows attackers to potentially access sensitive private GPG keys stored on the server, creating significant risks for email security and data protection. The attack vector requires only network connectivity, making it particularly dangerous as it can be exploited remotely without requiring physical access or additional authentication credentials.
The technical flaw resides in the enigma plugin's inadequate permission controls when handling GPG key files and related cryptographic operations. This insecure permissions vulnerability creates a path for unauthorized access to private key material that should remain protected and restricted to authorized users only. The vulnerability enables an attacker to read files that contain private GPG keys, which can then be used to decrypt sensitive communications, impersonate legitimate users, or perform man-in-the-middle attacks on encrypted email exchanges. The issue directly relates to CWE-732, which describes improper permission assignment where security-critical resources are accessible to unauthorized actors due to weak access controls.
The operational impact of this vulnerability extends beyond simple data theft, as private GPG keys can be used to decrypt past communications and potentially compromise long-term security of encrypted email exchanges. An attacker who successfully exploits this vulnerability can gain access to confidential business communications, personal correspondence, and potentially sensitive corporate data that was intended to be protected through end-to-end encryption. This represents a significant risk for organizations relying on Roundcube for secure email communications, particularly those in regulated industries where email encryption is mandated. The vulnerability also creates opportunities for credential theft and further lateral movement within network environments, as private keys often serve as authentication tokens for various systems and services.
Mitigation strategies for CVE-2018-1000071 should prioritize immediate patching of Roundcube installations to versions 1.3.5 or later where the permission handling has been corrected. Organizations should also implement additional security controls including restricting network access to Roundcube installations, implementing proper file system permissions for GPG key directories, and conducting thorough security audits of cryptographic key management practices. System administrators should review and tighten access controls for all cryptographic material, ensuring that private key files are stored with appropriate permissions that prevent unauthorized reading or copying. The vulnerability demonstrates the critical importance of proper access control implementation in cryptographic systems, aligning with ATT&CK technique T1552.001 for credentials in files, and emphasizes the need for regular security assessments of web application components that handle sensitive cryptographic operations.